Dimethyltin ester stabilizers for vinyl-halide polymers

ABSTRACT

Dimethyltin derivatives of lower toxicity are prepared by reducing the amount of trimethyltin impurity.

United States Patent Weisield et a1.

DIMETHYLTIN ESTER STABILIZERS FOR VlNYL-HALIDE POLYMERS inventors: Lewis B. Weisield, Princeton, N.J.;

Robert C. Witman, Cincinnati, Ohio Cincinnati Milacron Chemicals, Inc., Reading, Ohio ,Assignee:

Notice: The portion of the term of this patent subsequent to May 14, 1991 has been disclaimed.

Filed: Jan. 21, 1974 ,Appl. No.: 435,264

Related US. Application Data Continuation-impart of Ser. Nos. 177,516, Sept. 2, 1971, and Ser. No. 317,228, Dec. 21, 1972, Pat. No. 3,810,868.

Foreign Application Priority Data Germany 2329039 June 7, 1973 1 *June 3, 1975 [52] US. Cl 260/45.75 K; 252/406 Primary Examiner-V. P. Hoke Attorney, Agent, or FirmCushman, Darby & Cushman [5 7] ABSTRACT Dimethyltin derivatives of lower toxicity are prepared by reducing the amount of trimethyltin impurity.

30 Claims, N0 Drawings DIMETHYLTIN ESTER STABILIZERS FOR VINYL-HALIDE POLYMERS The present application is a continuation-in-part of application Ser. No. 177,516, filed Sept. 2, 1971 and of application Ser. No. 317,228, filed Dec. 21, 1972 now U.S. Pat. No. 3,810,868 issued May 14, 1974.

The present invention relates to dimethyltin compounds of reduced toxicity and their use as stabilizers for halogen containing resins.

According to the present invention there are prepared dimethyltin compounds having the formula where R, and R are -S(CH ),,COOR S(Cl-l ,COOROCO(Cl-l ),,S, OR.,, SR OCOCH CHCOOR OCOR chlorine or R and R together are either S or O. In the formula R R R and R are hydrocarbon or divalent sulfur (thioether) substituted hydrocarbon or oxygen (ether) substituted hydrocarbon, e.g., alkyl, cycloalkyl, alkenyl, benzyl, tolyl, phenyl, of up to 20 carbon atoms, preferably 4 to 12 carbon atoms, 11 is an integer of 1 to 3 and R is a divalent hydrocarbon (alkylene), chlorine substituted divalent hydrocarbon, divalent sulfur (thioether) or oxygen (other substituted hydrocarbon of 2 to 6 carbon atoms.

Typical compounds of this type are shown in Mack U.S. Pat. No. 2,684,973, Langkammerer U.S. Pat. No. 2,253,128, Ouattlebaum U.S. Pat. No. 2,307,157, Leistner U.S. Pat. No. 2,641,596, Leistner U.S. Pat. No. 2,726,254, Best U.S. Pat. No. 2,731,484, Weinberg U.S. Pat. No. 2,746,946, Mack U.S. Pat. No. 2,809,956, Weinberg U.S. Pat. No. 2,832,750 and Weisfeld U.S. Pat. No. 3,640,950. The entire disclosure of Weisfeld, both Mack patents, Langkammerer, Quattlebaum, both Leistner patents, Best and Weinberg patents is hereby incorporated by reference.

Among the compounds of reduced toxicity prepared according to the invention are dimethyltin dichloride, dimethyltin oxide, dimethyltin sulfide, dimethyltin bis- (isooctyl thioglycolate dimetyltin bis(isooctyl-3- mercaptopropionate, dimethyltin bis (2-ethylhexy1thioglycolate), dimethyltin bis (2'-ethylhexyl-3-mercaptopropionate), dimethyltin bis (isooctyl 4-mercaptobutyrate dimethyltin bis (n-octyl thioglycolate), dimethyltin bis -n-octyl-3-mercaptopropionate), dimethyltin bis (methyl thioglycolate), dimethyltin bis (methyl 3-mercaptopropionate), dimethyltin bis (methyl 4-mercaptobutyrate), dimetyltin bis (ethyl thiolglycolate dimethyltin bis(propyl 3-thiopropionate), dimethyltin bis(butyl thioglycolate), dimethyltin bis(butyl 3-thiopropionate dimethyltin bis (butyl-4- thiobutyrate), dimethyltin bis (isooctyl 2-thiopropionate), dimethyltin bis (decyl thioglycolate), dimethyltin bis (dodecyl thioglycolate), dimethyltin bis (dodecyl 3thiopropionate), dimethyltin bis (dodecyl 4- thiobutyrate), dimethyltin bis (octadecyl thioglycolate), dimethyltin bis (octadecyl 3-thiopropionate), dimethyltin bis (octadecyl 4-thiobutyrate), dimethyltin bis (cicosanyl thioglycolate), dimethyltin bis(cicosanyl -3-thiopropionate), dimethyltin bis (cyclopentyl thioglycolate), dimethyltin bis (cyclohexyl thioglycolate), dimethyltin bis (cyclohexyl-3-thiopropionate), dimethyltin bis (benzyl thioglycolate), dimethyltin bis(benzyl-3-thipropionate) dimethyltin bis (phenyl thioglycolate), dimethyltin bis(p-tolyl-3-thiopropionate), dimethyltin bis (allyl thioglycolate), dimethyltin bis (allyl-3-thiopropionate), dimethyltin bis (allyl-4- thiobutyrate), dimethyltin bis(crotyl thioglycolate), dimethyltin bis(oleyl thioglycolate dimethyltin bis (oleyl-3-thiopropionate), dimethyltin bis (oleyl-4- thiobutyrate), dimethyltin octyl thioglycolate decyl thioglycolate, dimethyltin bis(methallyl thioglycolate), dimethyltin bis (methallyl-3-thiopropionate), dimethyltin bis(dodecenyl thioglycolate, dimethyltin dimethoxide, dimethyltin dibutoxide, dimethyltin diisooctoxide,

dimethyltin didodecoxide, dimethyltin dioctadecoxid dimethyltin dimethyl mercaptide, dimethyltin diethyl mercaptide, dimethyltin dipropyl mercaptide, dimethyltin dibutylmercaptide, dimethyltin diisooctylmercaptide, dimethyltin di(2-ethylhexyl mercaptide), dimethyltin dioctyl mercaptide, dimethyltin didodecyl mercaptide, dimethyltin dioctodecyl mercaptide, dimethyltin dieicosanyl mercaptide, dimethyltin diallyl mercaptide, dimethyltin dioleyl mercaptide, dimethyltin dicyclohexyl mercaptide, dimethyltin diphenyl mercaptide, dimethyltin dibenzyl mercaptide, dimethyltin diacetate, dimethyltin dipropionate, dimethyltin dibutyrate, dimethyltin divalerate, dimethyltin dihexanoate, dimethyltin dioctanoate, dimethyltin didecanoate, dimethyltin dilaurate, dimethyltin dimyristate, dimethyltin dipalmitate, dimethyltin distearate, dimethyltin dieicosanoate, dimethyltin methoxy acetate, dimethyltin methoxy oleyl maleate, dimethyltin butoxy octadecyl maleate, dimethyltin ethoxy methyl maleate, dimethyltin propoxy isooctyl maleate, dimethyltin di(methylmaleate), dimethyltin di (ethylmaleate), dimethyltin di (propylmaleate), dimethyltin di (butylmaleate), dimethyltin di(octylmaleate), dimethyltin di (isooctyl maleate), dimethyltin di (2-ethylhexyl maleate), dimethyltin di(benzyl maleate), dimethyltin di (dodecyl maleate), dimethyltin di (octadecyl maleate), dimethyltin di (phenyl maleate dimethyltin di (oleyl maleate), dimethyltin di (allyl maleate), dimethyltin diacrylate, dimethyltin dimethacrylate, dimethyltin dicrotonate, dimethyltin ethylene bis thioglycolate (the reaction product of dimethyltin dichloride with ethylene bis thioglycolate of the formula HSCl-l COOCl-I C- H OOCCH SH), dimethyltin propylene bis (thioglycolate), dimethyltin trimethylene bis(thioglycolate), dimethyltin hexamethylene bis(thioglycolate), dimethyltin ethylene bis (3-thiopropionate), dimethyltin diethyleneglycol bis (thioglycolate), dimethyltin thiodiglycol bis (thioglycolate). The products containing divalent groups such as S(CH ),',COOROCO (CH ),,S preferably are prepared using chain stoppers such as S(Cl-l ),,COOR in proportions to give small polymers.

Other compounds within formula I include dimethyltin bis (2-chloroethyl thioglycolate), dimethyltin bis (3- chloropropyl thioglycolate), dimethyltin bis (2'- chloroethyl-3-thiopropionate), dimethyltin bis (methoxyethyl thioglycolate), dimethyltin bis (methoxypropyl thioglycolate), dimethyltin bis (ethoxyethyl-3- thiopropionate), dimethyltin bis(butoxyethyl thioglycolate), dimethyltin bis (ethoxyethoxy ethyl thioglycolate), dimethyltin bis (methylthioethyl thioglycolate), dimethyltin bis (methylthioethyl mercaptide).

While many organotin compounds have been proposed as stabilizers for polyvinyl chloride (PVC), e.g., see Weinberg US. Pat. No. 2,648,650, Leistner US. Pat. No. 2,641,596, Kauder US. Pat. No. 3,222,317 and Hechenbleikner US. Pat. No. 3,396,185, from their inception the organotin stabilizers employed commercially have all been butyltin products except for the use of octyltin stabilizers for food contact articles. The most important organotin stabilizer is dibutyltin bis- (isooctyl thioglycolate) available commercially under the trademark ADVASTAB "FM-180. While many tin stabilizer patents since about 1950 have included an R group of l to 8 or more carbon atoms attached to the tin, only butyls and to a lesser extent octyls have in fact been used commercially. The propyl tins are known to have an obnoxious odor, ethyl tin compounds are toxic. Methyltin compounds have been considered water soluble, insufficiently compatible with polyvinyl chloride and to have toxicity problems, particularly as skin irritants.

Historically, the largest producer of organotin compounds in the United States is M & T Chemicals, Inc. In :1 Symposium on Polyvinylchloride Stabilization Status and Trends" presented at the 160th American Chemical Society meeting in Chicago, Illinois in the fall of 1970 a nine-page paper was presented by A. .l. Ejk and W. A. Larkin of M & T Chemicals, Inc. on Organotin Stabilization. This article states on page 2 that tetravalent butyltin compounds are of prime impor tance as organotin stabilizers and points out defects in all other alkyltin compounds. Thus it states that methyltin compounds are soluble in water. Among the more useful organotin stabilizers is listed dibutyltin S,S' bis (isooctyl mercapto acetate). The article further points out that organotin compounds are frequently used in synergistic mixtures which include various mercaptides and carboxylates as well as zinc soaps (e.g. zinc stearate), phosphites (e.g. triphenyl phosphite), epoxies (e.g. epoxidized soya bean oil), glycerides, UV absorbers and/or antioxidants. Ejk et a1. classify tin stabilizers for polyvinyl chloride (PVC) as normal (tin content 16-18%) high (tin content 23-25%) and low (tin content 7-8%) efficiency stabilizers. Normal are preferred, high efficiency stabilizers presenting dispersibility problem because of their low use. It will be observed that dimethyltin bis (isooctyl thioglycolate) has a tin content of 21.4% and dimethyltin bis (isooctyl mercaptopropionate) has a tin content of 20.4%.

Ejk et al. also show that di (n-octyl) tin S,S' bis (isooctyl mercapto acetate) is a commercial stabilizer. The octyltin compounds are stated to be somewhat lower in tin content and to offer increased lubricity compared to their butyltin counterparts. Ejk et al. state that butyltin stabilizers possess unsurpassed stability to PVC homopolymers and copolymers while only octyltin stabilizers provide the stability, clarity and blush resistance properties required for PVC food packaging. Ejk et al. also point out that an extended production run is the only true test for a stabilizer but that laboratory tests can be used to evaluate candidates and keep the number of production runs at a minimum.

Dynamic mill stability is among the most popular methods for evaluating the dynamic activity of a stabilizer.

The water solubility of methyltin compounds is shown for example in Mack et al. US. Pat. No. 2,914,506 example 10 wherein dimethyltin, S,S' bis 3, (2,3-dihydroxypropyl mercaptide) is shown to be completely water soluble while the corresponding dibutyltin compound is not water soluble. Dimethyltin dichloride is also known to be water soluble.

Barnes and Stoner in British Journal of Industrial Medicine Vol. 15 pages 15-22 (1958) report on the Toxic Properties of Some Dialakyltin and Trialkyltin Salts. The article indicates that dimethyltin dichloride, while less toxic than other dialkyltin dichlorides when injected intravenously into rats, when tested on the skin produced severe superficial damage in rats and guinea pigs. Orally it was toxic in a dosage of mg/kg. Barnes and Stone also pointed out that dibutyltin di-isooctyl thioglycolate had no significant toxic differences from dibutyltin dichloride when applied orally. Trimethyltin acetate had an oral toxicity 40 times greater than that of tributyltin acetate. The trimethyl compound also was water soluble.

Barnes (coauthor of the above article) and Magos Organometal. Chem. Rev. Vol. 3 pages 137-150 Toxicology of Organometallic Compounds on pages 143145 discusses dialkyl and trialkyltin compounds. The article points out on page 144 that the higher homologues, dibutyl and dioctyltin salts are important stabilizers in PVC and that the lower dialkyltin compounds are intense and acute irritants and damage the skin. In contrast dibutyltin salts are stated to be not sufficiently irritating to produce skin damage. From animal studies it is stated that it would seem probable that dimethyltin salts would damage human skins.

On page 145 it is pointed out that triethyltin compounds are toxic by mouth or by injection and that trimethyltin compounds are similarly toxic while tributyltin compounds are indicated as having a lower toxicity.

Kirk Othmer Encyclopedia of Chemical Technology, 1st edition Second Supplement (1960), on page 541 points out that dimethyltin dichloride derivatives are not too compatible with polyvinyl chloride and hazy films result.

TM- is a commercial dibutyltin bis (isooctyl thioglycolate). TM-181 is commercial dimethyltin bis (isooctyl thioglycolate) of the present invention.

Acute oral toxicity and primary skin and acute eye irritation studies were made on TM-l80 and TM-18l using the techniques specified in the Regulations for the Enforcement of the Federal Hazardous Substances Act (Revised, Federal Register, September 17, 1964). Oral toxicity (LD for TM-180 was 1037 mg/kg and TM-l8l had an oral LD of 1102 mg/kg. In the Patch Test for Primary Skin Irritation TM- 1 80 had a Primary Irritation Index of 6.99 while TM-l81 had a Primary Irritation Index of 2.36.

Eye application of TlVl-180 to rabbits produced moderate or marked conjunctivitis and thickening and fissuring of the eyelids in each rabbit tested while with TM-181 there was no irritative effects involving the cornea, iris or conjunctival.

The Summary of the report of TMl 80 classified TM- 180 as toxic, but not highly toxic, by ingestion; is a primary skin irritant, but not a corrosive material; and is an eye irritant while Tl\/l18l is classified as toxic, but not highly toxic, by ingestion; is not a primary skin irritant or corrosive material; and is not an eye irri tant.

The lack of skin irritation is surprising in view of the Barnes and Stoner results set forth in Table 5 in regard to dimethyltin dichloride.

In water solubility tests both TM-180 and TM-l8l proved to be quite insoluble, the solubility being about 0.025% for both compounds. Water extraction tests on polyvinyl chlorido pipe containing TM-l80 and TM- 181 were conducted according to the National Sanitation Foundation (N.S.F.) tests at the indicated stabilizer levels in parts per hundred resin (phr).

Compound phr 72 hr. 100F. distilled 11-1 0 parts per million 1 ppm) stabilizer extracted TM-l 80 0.6 3 TM-181 0.54 1

72 hr. 100F. Distilled Water ppm Stabilizer Extracted Compound phr A B TM-l 81 is thus non extractable by water from rigid PVC (less than 1 ppm) and has been approved by the National Sanitation Foundation for use in potable water pipe. Previously the dibutyltin analogue was the sole approved tin stabilizer for such use. The suitability of the dimethyltin bis(isooctyl thioglycolate) for such purpose is particularly surprising in view of the belief that dimethyltin compounds in general are water soluble.

While TM-181 is slightly more volatile than TM-180 (about 20-25C.) on thermogravimetric analysis (complete loss for TM-l 81 for 3 samples average 279C. and for TM-l80 averaging 301C. while the temperature at which 50% of the material was gone for TM-181 was 223C. and for TM-l80 was 245C.) this is not observable in actual use. Thus in Brabender experiments with PVC at variable and high concentrations at elevated temperatures (440F), no loss in stabilization with TM-l 81 was noted and if there is any difference in loss of stabilization with TM-l 81 over TM- 180 in PVC processing, it is not apparently significant.

To reduce toxicity for formulations containing dimethyltin bis(isooctyl thioglycolate) it should be as free as possible from trimethyltin isooctyl thioglycolate. The oral toxicity of a sample of an alkyltin compound can be determined relatively accurately by the equation M TD/C,(D T) T where D=LD S0 of the dialkyltin compound in mg/kg body weight T=LD 50 of the trialkyltin compound in mg/kg body weight M=LD 50 of the binary mixture, mg/kg of body weight and C1 decimal concentration of the trialkyltin compound in the binary compound.

6 Using D for dimethyltin bis(isooctyl thioglycolate) of 1380 and T for trimethyltin isooctyl thioglycolate of 24 (both values determined experimentally) the following results are obtained by the equation and compared with actual oral toxicity results.

M(cale) 1380 1076 882 747 648 512 361 208 24 M(exp) 1380 1020 695 376 24 It has been found that dimethyltin bis(isooctyl thioglycolate) is an exceptionally good stabilizer for vinyl chloride polymers, much better than dibutyltin bis- (isooctyl thioglycolate). In laboratory tests the superiority is not as marked as in production sized extruders where it seems on a practical basis to be up to twice as effective, pound for pound. The ability of TM-18l to maintain good early color in PVC is unmatched by TM- at any concentration. In the first 7 months since its commercial introduction over 200,000 pounds of TM-l8l have been sold and it is rapidly gaining widespread acceptance.

In at least one case a customer reported that TM-l 81 as a stabilizer resulted in fusion of rigid PVC much more quickly than with TM-180. Possibly this is due to TM-181 being more solvating or more plasticizing than TM-180 at elevated temperatures such as those occurring in extruders and other processing equipment.

TM-181 is described in its commercial literature as a liquid organotin, sulfur-containing PVC stabilizer possessing excellent compatibility and processing characteristics. It is essentially non-lubricating. TM-l81 furnishes equivalent performance to TM-l80 with much greater economy.

Typical Physical Properties Form Clear liquid Color (Gardner) 2-3 Specific Gravity at 75F 1.19 Viscosity at 75F. 66 cps Lbs/Gallon 9.9

(TM-181 also has an LD of over 1000 mg/kg.)

TM-l 80.

4. High compatibility with PVC promotes excellent clarityrecommended for blow molding.

5. Enhances fusion of PVC powder blends; contributes to lower melt viscosity.

6. Recommended for solution vinyl chloride systems containing reactive terpolymers, e.g. vinyl chloridevinyl acetate-maleic anhydride terpolymers such as 86- :l3zl, 85:l3:2, 84:133.

'7. Recommended for fluidized-bed powder coating applications.

While the use of dimethyltin bis (isooctyl thioglycolate) is preferred in the stabilizer compositions there can als be used dimethyltin bis (isooctyl mercapto propionate).

Unless otherwise indicated all parts and percentages are by weight.

The stabilizers of the present invention can be used with halogen containing vinyland vinylidene resins in which the halogen is attached directly to the carbon atoms. Preferably, the resin is a vinyl halide resin, specifically, a vinyl chloride resin. Usually, the vinyl chloride resin is made from monomers consisting of vinyl chloride alone or a mixture of monomers comprising at least 70% vinyl chloride by weight. When vinyl chloride copolymers are stabilized, preferably the copolymer of vinyl chloride with an ethylenically unsaturated compound copolymerizable therwith contains at least 10% of polymerized vinyl chloride.

As the halogen resin there can be employed chlorinated polyethylene having 14 to 75%, e.g. 27% chlorine by weight, polyvinyl chloride, polyvinylidene chloride, polyvinyl bromide, polyvinyl fluoride, polyvinylidene fluoride, copolymers of vinyl chloride with 1 to 90%, preferably, 1 to 30%, of a copolymerizable ethylenically unsaturated material such as vinyl acetate, vinyl butyrate, vinyl benzoate, vinylidene chloride, diethyl fumarate, diethyl maleate, other alkyl fumarates and maleates, vinyl propionate, methyl acrylate, 2- ethylhexyl acrylate, butyl acrylate and other alkyl acrylates, methyl methacrylate, ethyl methacrylate, butyl methacrylate and other alkyl methacrylates, methyl alpha choroacrylate, styrene, trichloroethylene, vinyl ethers such as vinyl ethyl other, vinyl chloroethyl ether and vinyl phenyl ether, vinyl ketones such as vinyl methyl ketone and vinyl phenyl ketone, l-fluoro-lchloroethylene, acrylonitrile, chloroacrylonitrile, allylidene diacetate and chloroallylidene diacetate. Typical copolymers include vinyl chloridevinyl acetate (96.4 sold commercially as VYNW), vinyl chloridevinylacetate (87:13), vinyl chloride-vinyl acetate- Maleic anhydride (86:l3:l), vinyl chloride-vinylidene chloride (95:5), vinyl chloride-diethyl fumarate (95:5) vinyl chloride-trichloroethylene (95:5), vinyl chloride- Z-ethylhexyl acrylate (80:20).

The stabilizers of the present invention can be incorporated with the resin by admixing in an appropriate mill or mixer or by any of the other well-known methods which provide for uniform distribution throughout the resin compositions. Thus, mixing can be accomplished by milling on rolls at 100-160C.

In addition to the novel stabilizers there can also be incorporated with the resin conventional additives such as plasticizers, pigments, fillers, dyes, ultraviolet light absorbing agents, densifying agents and the like.

If a plasticizer is employed, it is used in conventional amount, e.g. 30 to 150 parts per 100 parts of resin. Typical plasticizers are di-Z-ethylhexyl phthalate, dibutyl sebacate, dioctyl sebacate, tricresyl phosphate.

The tin containing stabilizers are normally used in an amount of 0.01 to 10% by weight of the resin, more preferably 0.1 to 5% of the tin compound is used by weight of the resin.

There can also be included with the novel stabilizers of the present invention conventional stabilizers and antioxidants to assist in improving the properties of the halogen containing resin. Thus there can be included 0.0ll0%, preferably 0.1-5% based on the resin of sulfur containing compounds such as dilauryl-thiodipropionate, distearyl 3,3'-thiodipropionate, dicyclohexyl- 3,3-thiodipropionate, dicetyl-3,3-thiodipropionate, dioleyl-3,3'-thiodipropionate, dibenzyl-3,3'-thiodipropionate, di-p-methoxyphenyl-3 ,3 -thiodipropionate, didecyl-3 ,3 -thiodipropionate, dibenzyl-3 ,3 -thiodipropionate, diethyl-3,3'-thiopropionate, lauryl ester of 3-methylmercaptopropionic acid, lauryl ester of 3-butylmercaptopropionic acid, lauryl ester of 3-lauryl mercaptopropionic acid, phenyl ester of 3-octyl mercaptopropionic acid,

There can also be included 0.1-10%, preferably 0.1-5% by weight of the halogen containing resin of metal salt stabilizers such as Groups I and 11 metal soaps, e.g. calcium stearate, calcium Z-ethylhexeate, calcium octoate, calcium oleate, calcium ricinoleate, calcium myristate, calcium palmitate, calcium laurate, barium laurate, barium stearate, magnesium stearate, zinc stearate, cadmium laurate, cadmium octoate, cadmium stearate and sodium stearate. Other metal salts can be used as lead stearate, lead silicate, aluminum stearate, etc.

There can also be added phenolic antioxidants in an amount of 0.01-10%, preferably 0.1-5%. Examples of such phenols include 2,6-di-t-butyl-p-cres0l, butylated hydroxyanisole, propyl gallate, 4,4'-thiobis(6-t-butylm-cresol), 4,4'-cyclohexylidene diphenol, 2,5-di-tamyl hydroquinone, 4,4'-butylidene bis(6-t-butyl-mcresol), hydroquinone monobenzyl ether, 2,2- methylene-bis(4-methyl-6-t-butyl phenol), 2,6-butyl-4- decyloxy phenol, 2-t-butyl4-dodecyloxy phenol, 2-tbutyl-4-dodecyloxy phenol, 2-t-butyl-4-octadecyloxy phenol, 4,4'-methylene-bis(2,6-di-t-butyl phenol), pamino phenol, N-lauryloxy-p-amino phenol, 4,4- thiobis(3-methyl-6-t-buty1 phenol), bis [o-(l,l,3,3- tetramethyl butyl)phenol] sulfide, 4-acetyl-B- resorcylic acid, A stage p-t-butylphenolformaldehyde resin, 4-dodecyloxy-2-hydroxybenzophenone, 3-hydr0xy-4-(phenylcarbonyl) phenyl palmitate, ndodecyl ester of 3-hydroxy-4-(phenyl carbonyl) phenoxyacetic acid, and t-butyl phenol.

The use of epoxy compounds in an amount of 0.01-5% in the polymer compositions is also valuable. Examples of such epoxy compounds include epoxidized soya bean oil, epoxidized lard oil, epoxidized olive oil, epoxidized linseed oil, epoxidized castor oil, epoxidized peanut oil, epoxidized corn oil, epoxidized tung oil, epoxidized cottonseed oil, epichlorhydrinbisphenol A resins(epichlorhydrindiphenylolpropane resins),-phenoxy-propylene oxide, butoxypropylene oxide, epoxidized neopentylene oleate, glycidyl epoxystearate, epoxidized a-olefins, epoxidized glycidyl soyate, dicyclopentadiene, dioxide, epoxidized butyl tollate, styrene oxide, dipentene dioxide, glycidol, vinyl cyclohexene dioxide, glycidyl ether of resorcinol, glycidol ether of hydroquinone, glycidyl ether of 1,5- dihyroxynaphthalene, epoxidized linseed oil fatty acids, allyl glycidyl ether, butyl glycidyl ether, cyclohexane oxide, 4-(2,3-epoxypropoxy) acetophenone, mesityl oxide epoxide, 2-ethyl-3-propyl glycidamide, glycidyl ethers of glycerine, pentaerythritol and sorbitol, and

3 ,4-epoxycyclohexane-1 ldimethanol bis-9,10- DIMETHYLTIN epoxystearate. BIS(ISOOCTYLTHIOGLYCOLATE) Likewise there can be used organic phosphites in an EXAMPLE 1 l i l S T (c t 1101 2115021 os ii (cnggn,sc c re ga amount of 0.01 to 10%, preferably 0.1-% of the halo- To a mixture of 204.3 parts (1.0M) of isooctylthiogen containing resins. glycolate, 150 parts of water, 84 parts (1.0M) of so- The organic phosphites contain one or more, up to a dium bicarbonate and 300 parts of heptane there was total of three, aryl, alkyl, aralkyl and alkaryl groups, in added a solution of dimethyltin dichloride, prepared by any combination. The term trialkylaryl is inclusive of dissolving 107.5 grams (0.49M) of dimethyltin dichloalkyl, aryl, alkaryl and aralkyl phosphites containing ride containing 0.5% trimethyltin chloride, in 110 any assortment of alkyl, aryl, alkaryl and aralkyl grams of water, over a 1 hour period at -30C. After groups. Exemplary are triphenyl phosphite, tricresyl stirring an additional hour the lower aqueous layer was P P ethylphenyl) phosphite, tributyl removed and after washing with 150 grams of water the phosphite, trioctyl phosphite, tridoecyl phosphite, octyl organic layer was dried and stripped under vacuum to diphenyl phosphite, dioctyl phenyl phosphite, tri(octyl- 100C. The resulting product (dimethyltin bis(isooctylphenyl) phosphite, tri (nonylphenyl) phosphite, triben- 2O thioglycolate) consisted of 270 parts (98%) of a colorzyl phosphite, butyl, dicresyl phosphite, octyl di(octylless oil containing 21% tin, 11.4% sulfur and having a phenyl) phosphite, tri (Z-ethyl-hexyl) phosphite, tritorefractive index of 1.5100 and specific gravity of 1.19 lyl phosphite, tri(2-cyclohexylphenyl) phosphite, trit 25C.

alpha naphthyl phosphite, tr1(phenylphenyl) phos EXAMPLE 2 phite, and tri(2-phenylethyl) phosphite. 102.2 parts of isooctylthioglycolate (0.5M) were Of course there can also be incorporated 0.0110% heated with 41 parts (0.25M) of dimethyltin oxide of conventional organometallic stabilizers such as the (prepared from dimethyltin dichloride containing 0.5% known organotin carboxylates and mercaptides if detrimethyltin chloride) for 1 hour at 100C. under vacsired. Such materials include butyltin tris dodecyl meruum. The yield was 138.5 parts (100%) of dimethyltin capt1de,d1butyltin dilaurate, dibutyltin didodecyl mar bis(isooctyl thioglycolate) with properties similar to captide, dianhydride tris dibutylstannane diol, dihydrothose in example 1. carbontin salt f b t l h s 0 car oxy mercap a s suc as those set DIMETHYLTIN forth in Hechenbleikner et a1. U.S. Pat. No. 3,078,290. There can be included any of the vinyl chloride resin BISGSOOCTYL'3'MERCAPTOPROPIONATE) stabilizers set forth in Salyer US. Pat. No. 2,985,617. 40 EXAMPLE 3 9 lciisnc 1 l 1 HoCH Cl1 C 00 1 7 (CP Sn(SC1 C c 00 1i Likewise there can be included polyol stabilizers for In a 1 liter flask there were placed 218.5 gms. (1.0M)

vinyl chloride resins in an amount of 0.01-10%. Thus of isooctyl-3-mercaptopropionate, 200 grams of water, there can be included glycerol, sorbitol, pentaerythritol 84 grams (1.0M) of sodium bicarbonate and 300 gms.

and manniwl' of heptane. To this slurry was added a solution of 109.7 Nitrogen Containin Stabilizers such a grams (0.50M) of dimethyltin dichloride (containing amide me! g f lcyan 0.5% of trimethyltm chloride) in 1 10 grams over a one amme urea Ormoguanamme dlmethyl hour period. After a short stirring period the organic dantoin guanidine thiourea and the like also can be layer was separated, washed and stripped under vacllcluded ameums W be uum, resulting in a 287 gram yield 99% of dimethylc uded conventional lubricants for vinyl chloride resins tin biisooctyl 3 mercaptopropionate) a l l s oil,

such as low molecular weight polyethylene ie poly- This compound had a refractive index at 25 of 1.5062 ethylene wax, fatty acid amides, e.g. lauramide and stearamide bisamides e g decamethylene bis amide a tin content of 20.3% and a sulfur content of 10.8%. and fatty acid esters, e.g. butyl stearate, glyceryl stea- EXAMPLE 4 i o H S n i C (C113) one 1 211 011 011 0 00 1 1 9 (Cll3) Sn(bC en s CC8lil7)2-rl rate, linseed oil, palm oil, decyl oleate, corn oil, cotton- In a U2 liter flask 65.9 grams of dimethyltin oxide seed oll, hydrogenated cottonseed oil, etc. (0.40M) was heated with 174.7 grams (0.80M) of isooctyl-3-mercaptopropionate for 1 hour at 100C. under an absolute pressure of 2mm of Hg. The colorless oil prepared in this manner was cooled and filtered to yield 232 grams of dimethyltin bis(isooctyl-3-mercapatopropionate).

DISPROPORTIONATION EXAMPLE 5 A sample of dimethyltin dichloride having a trimethyltin content of 5.0% was used to prepare dimethyltin bis(isooctylthioglycolate) by the method given in example 1. This product had an LD value of 380. Whenthis same dimethyltin dichloride (containing the 5.0% trimethyltin chloride) was heated at 120C. for 2 hours with 2.6% by weight of stanriic chloride, the trimethyl-' 112 a methyl methacrylate polymer (90% methyl methacrylate--l0% ethyl acrylate).

Advawax 165 is paraffin wax. Advawax 280 is ethylene bis(stearamide).

Twin Screw 375F. Oven Stabilizer Parts 1st Color (Mins.) Failure (Min.)

TM-l80 0.40 10 40 TM-l8l 0.36 50 Single Screw 400F. Oven Stabilizer Parts 1st Color (Mins.) Failure (Min.)

TM180 1.40 10 TMl81 1.25 15 Conclusion: TM-181 furnishes better color stability than TM-180 to both a single screw and a twin screw type of polyvinyl chloride pipe compound.

3. Processing Stability Brabender Plastograph Conditions 220C.; rpm, charge grams tin chloride content was reduced to 0.5% and dimethyl- 20 The formulation employed was the Twin Screw fortin bis(isooctylthioglycolate) prepared from this rnatemulation used in Example 6 part 2 with the parts of starial had an LD rating of 1020. bilizer indicated below.

Stabilizer Parts Fusion Max Torque Stability Minimum (time min.) (time min) Torque Low TM-180 0.40 2.2 2700 3.7 1900 Level TM-l8l 0.36 1.8 3425 5.6 1725 lnter- TM-l 0.60 3.8 2400 6.1 1600 mediate Level TM-l8l 0.53 1.7 3950 6.9 1725 High TM-lSO 0.80 1.5 3200 8.7 1600 Level TM-l8l 0.72 1.2 3850 9.0 1600 EXAMPLE 6 TM-18l was compared with TM-180 as a stabilizer for Geon 103 E? (a polyvinyl chloride medium molecular weight homopolymer).

l. Oven Stability at 360F. Test Formulation Geon 103 parts Bistearyl azelate containing 5% free stearic acid 0.5 parts Stabilizer As indicated Time in Minutes TM 0 15 30 45 6O 75 90 phr Color TM-l80 1.0 1 4 4 4 4 6 9 l0 TM-18l 1.0 1 2 2 2 3 5 8 10 TM-lBl 0.875 1 2 2 2 4 7 10 TM-l81 0.8 1 2 2 3 5 9 1O TM-181 0.75 1 2 2 3 7 10 Color Scale 1 to 10 Conclusion: TM-181 offers superior early color over TM-180 even at significantly lower levels.

2. Over Stability; twin and single screw extrusion formulations Twin Screw Single Screw Geon 103 100 parts Geon 103 100 parts K N 1.5 K 120 N 3.0

TiO 1.0 TiO 1.0

Ca stearate 0.4 Ca stearate 1.0

Advawax 1.4 Advawax 280 0.75

Stabilizer as indicated Stabilizer as indicated K 120 N is a commercial acrylic processing aid, it is Conclusion: TM-181 is clearly superior to TM- in processing stability and color stability during processing even at a 10% lower use level. As the total stabilizer level is reduced the advantage shown by TM-18l is more pronounced.

4. Twin Screw Extrusion A series of pipe extrusions were carried out in Linz, Austria on an AGM CT 90/6 conical twin screw extruder using TM-l80 and TM-l 81 in the preparation of 2-inch SDR 21, Type 1, Grade I pipe.

Formulation 1 Formulation ll Conclusion: TM-l 81 exhibited a higher output rate and excellent overall performance at a 10 lower use level.

inches 24:1 cxtruder the compounds were extruded from powder, then subjected to two additional extrusions from regrind. TM-l8l performed successfully in this evaluation.

6. Corrosive Properties Several commercial tin stabilizers are highly acidic in 10 nature, and in fact contained 1.8 to 2.0 chlorine which is readily hydrolyzed, forming HCl.

Steel bars were immersed in TM-l81 and one such competitive commercial stabilizer and allowed to stand at room temperature for several days. Severe corrosion EXAMPLE 7 This example further shows the performance profile for TM- 1 8 l.

1. Dynamic Processing Stability Formulation Econ [03 EP 100.0 parts K 120 N 2.0 Chlorinated Polyethylene lClPE) .20 Titanium dioxide 1.5

Continued 1. Dynamic Processing Stability Formulation Advawax 280 1.0

Calcium stearate 10 Mill TM-l8l as indicated Mill Dynamic, 390F. Brabender, 190C,

0 rpm, grams phr 1st color Failure 1st color Failure 1.6 20 minutes 26 minutes 12 minutes 18 minutes 1.4 18 minutes 24 minutes 10 minutes 14 minutes At equal levels TM-l8l furnished about 8% greater stability (both early color and ultimate processing stability) than a competitive commercial tin stabilizer. At a 12% lower use level TM-l8l furnished equivalent two roll mill dynamic stability and slightly less Brabender stability.

Failure is indicated in the above tests by sticking or bad color or both.

2. Injection Molding of Pipe Fittings A comparison was made of TM-l8l (1.7 phr) and TM-l (2.0 phr) stabilized polyvinyl chloride pipe fitting compounds in an HPM reciprocating screw injection molding machine. Pipe fittings containing the TM- 181 were whiter than the TM-l80 stabilized fittings, which exhibited slight burning near the gates.

3. Pipe Extrusion Trial The performance of TM-18l in a variety of single and twin screw extractors and comparison with TM- 180 is illustrated by the following representative extrusion runs.

"standard is TM-180 B. Single Screw Extrusion Extruder Type Pipe Size Stabilizer Usage Output Pipe Quality (inches) Level lbs/hr Appearance Predex:

3- /z" 24:1 8 TM-180 standard 320 3-5 2" 24:1 8 TM-l8l 10% below standard 328 Excellent Whiter than standard 4 k" 24:1 12 TM-l80 standard 700 4-%" 24:1 12 TM-l8l 15% below standard 700 Excellent whiter than standard 2- /a" 24:1 2 TM-l80 standard Z-W' 24:1 2 TM-18l 15% below Whiter than standard 170 standard Davis Standard 3-5? 24:1 4 TM- 1.0 phr 386 production standard 3-92" 24:1 4 TM-lSl 0.9 phr 383 Equivalent to standard 3- /2" 24:1 4 TM-l8l 0.85 phr 392 Equivalent to standard 3-92" 24:1 4 TM-18l 0.80 phr 406 2O001psi), and (c) TM-118l can be used in high idi'stor- 1 tion teleduct (conduit) PVC. 1 1 1 1 1 1 As used in the present specification and clairnsthe 11 is'ooctyl group is the mixture ofisom'er'sp'roduced in the 1 1 oxo process. This is the normal meaning of"isooctyl 1 whenused withconv'entionali tinistabilizers such as di- 1' 1 1 butyltln bis 1 (isooet'yl' thiog lycolate) as: is F setforth in 1 1 1 1 1Kirk-Othrner1 Encyclopedia 1 of Chemical Technology:

; 1st edition. second supplement 1 960) page 54 0. A 1 1 1 1 1' 1 typical commercialmixtureofisomeric octyl alcohols 1 1 1 1 1 1 used to prepare the isooctyl1thioglyco1late is shown in 2 1 Kirk -Gthrner in page 1552 a d the 1 sage at t e term 1 ist) is explained on pages 55 3-554.

1 1 f 1 1 s; sed in the fci'laims the I term1 L05 01? at; least 1 I000 means that the T513501 is'at least 1000 or greater; 1

erg- 110001, 11100 or. I380.

1 The dimethyltin bist isooctyl mereaptoalkanoatesl of g methyltin bis(12 -ethylhexyl thioglycolateland dimethyl- 1 1 1 1 1 tin; b1is(21-ethylhexyhS mercaptopropionate.) as stabiliz- 1 I 1 ers ifori the, halogemcontaining resins; egg polyvinyl 1' i 1 Ichloride.1 The dimethyltin bis(2 -ethylhexyl rnercap 1 1 1 1 1 1 a 1toalkanoate)1can1 be prepared inanidentical manner to g 1 1 1 1 Conclusion: At lower use levels (1l0-130% lower) TM- 1 1 1 18 1 can provide bothhigher quality'and increased out-' 1 1 1 1 1 putrateson: twin and singlescrew pipe extrusion lines 1 1 1 than1TM 180 1 1 1 1 1 1 1 1 1 Customers have reported (a) that TM-18l is more 1 1 1 effective than TM-lSO in stabilizing chlorinated PVC 1 at high amperature; (b) that Type I PVC pipe having 1 a 2500 psi design stress rating has beenobtained with 1 1 TM -1l 8l1 (normal design stress for Type :1 PVC pipe is 1 1 1 l0 1 1 1 The products ofthe present invention preferably should have an L D; ,0 of at least 1000 when adminis-1 i 1 tered orally to ratsThis can be accomplished byassurs 1 1 1 1 1 1 1 1 1 1 1 1 1 ing that the trimethyltin content 1 1 1 1 1 1 1 1 1 in the dimethyltin compounds of formula Iis so low 1 1 1 1 1 that: not morethan: 0.715% ofthe tin as metal is in the 1 1 1 1 1 1 1 1 1 1 1 form of trimethyltincompounds. Any way which as- 1 I 1 I 1 I 1 I 1 1 1 sures thatthe amount of: tin present as trimethyltin 1 11 1 1 1 1 1 g 1 1 1 1 g I compound is not c ero 'is eprith Etiota'litin' a metal in i 1 5 i 1 1 i 1 1 f 1 1 1 i 1 1 1 the dimethyltin compounds can: be 1 used 1 to prepare 1 i 1 1 1 1 i1 1 1' 1 l 1 1' 1 i 1' 11 sucheompounds; Asindicated abovez, the starting :m a1 1 1 terials re; preferably madefrom dimethyltin dichloride 1 1 1 1 treated to reduce the trimethyltin chloride so that not 1 i over 0.7 5% of1the1 tinfas met al'is' presentlas rimethyltin; 1 1 1 i 1 1 1 E 1 1 1 i a 1 1 i 1 1 chloride. Using this starting material (or dimethyltin 1 1 i 1 1 1 i 1 1 I 1 I 1 1 1 oxide preparing therefrom) 1 conventional procedures 1 1 1 1 i are employed; such as'those illustrated in "examples 1 thatshown in example l,replacing theisooctylthid 1 glycolate by a mole of 2-ethylhexyl thioglycolate (or 1 mole of 2-ethylhexyl-3-mercaptopropionate).

It has now been found that not only the dimethyl compounds prepared and used in examples 1-7 can be prepared with low toxicity but that also all of the other compounds within formula I can likewise be prepared with low toxicity by reducing the amount of trimethyltin product in the same manner by preparing the materials either using dimethyltin dichloride of low toxicity due to the reduction in trimethyltin chloride, e.g., as prepared in example 1, or using dimethyltin oxide of low toxicity due to the reduction in trimethyltin compounds because of preparation of the dimethyltin oxide by the method indicated broadly in example 2.

The only change in the procedures normally used for the preparation of the compounds of formula I (which compounds are old per se) is to employ as a basic starting material dimethyltin chloride having a very low amount of trimethyltin chloride. It was not previously recognized that the presence of trimethyltin compounds was the reason for toxicity of dimethyltin compounds.

As shown in example 5 the amount of trimethyltin chloride present in dimethyltin dichloride is reduced by adding SnCl to dimethyltin dichloride. The use of excess SnCl e.g., 10% or 20% in the process of example 5 merely increases the amount of monomethyltin chloride in the dimethyltin dichloride but it further assures the reduction in amount of trimethyltin chloride.

1 1 I the invfintion a e eOmPatibIe w th fpolyvinylchlo ride as: 3 1 1 1 5 Less prgferably them can be used idlmethyltm i 1 1 1 i v n om t e da a P es n ed up a and do 1 m; 1 1 causehazyfilmsQ I I 1 1 1 :In place of the dimethyltin bis(isooctylmercaptoalk- 1 1 1 i amatel can be emplfiyed icorresplmding idle 1 i 1 1 1 Dimethym n sulfide can be prepared. forexample, by 1 i 1 i 1 1 1 1 reacting 1 more ofdimethyltin dichloridewith 1 male 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 of sodium sl lfide and compounds such as sodium 3 I I 1 5 methyl mercaptideor sodium isooctyl mercaptide. for 1 1 1 1 1 1, 1

example; can react with the purified dimethyltin di- 1 l 1 1 l 1 1 i 1 1 1 1 chloride by the conventional 1 procedure to form di- 2 1 1 i i 1 1 51 1 1 :1 1 1 1 3 1 (isoo'ctyl thioglycolat e l and anfy the other'dirniethyl- 1 1 f i l 1 tin compounds 1 having 'sufficient 1 trimethyltin com l 1 1 1 11 1 1 1 1 P un 1Q ha e 1 3 ,0 w 6 1 m g b d 11 E1 is 2 weight.

methyltin dimethylmercaptide or dimethyltin diisooctyl mercaptide. The general reaction procedures are further illustrated in Kirk-Othmer Encyclopedia of Chemical Technology, Second Supplement Volume (1960), pages 532-533.

In the case of dimethyltin bis(isooctyl thioglycolate) or dimethyltin bis(2-ethylhexyl thioglycolate) the amount of trimethyltin isooctyl thioglycolate present amounts to 0.5 weight this amount corresponding to about 0.75% of the total tin present calculated as metal being present as trimethyltin compound.

The amount of trimethyltin compounds present can be reduced to zero but is normally reduced to not over 0.15% of the total tin present calculated as metal since the greater the reduction in amount of trimethyltin compound the greater the increase in cost.

It has further been found that particularly valuable stabilizer compositions for any of the above identified halogen containing resins can be prepared if there is used a mixture of a compound having the formula l s (CH COOR cud s (CH c00R and a compound having the formula (2):

especially for food or potable water uses, of the compound having the formula (3):

where n and R are as defined above. Based on the total of(l), (2) and (3) the amount of(2) is 4 to 40%, more usually l929 weight percent and (l) is 96 to 60%, more usually 81-71 weight percent.

Typical compounds of formula (2) are:

methyltin tris(isooctyl thioglycolate),

methyltin tris(isooctyl-3-mercaptopropionate),

methyltin tris(2-ethylhexyl-thioglycolate),

methyltin tris(2'-ethylhexyl-3-mercaptopropionate),

methyltin tris(isooctyl-4-mercaptobutyrate),

methyltin tris(n-octyl thioglycolate),

methyltin tris(n-octyl-3-mercaptopropionate),

methyltin tris(methyl thioglycolate),

methyltin tris(methyl-3-mercaptopropionate),

methyltin tris(methyl-4-mercaptobutyrate),

methyltin tris(ethyl thioglycolate),

methyltin tris(propyl-3-thiopropionate),

methyltin tris(butylthioglycolate),

methyltin tris( butyl-3-thiopropionate),

methyltin tris(butyl-4-thiobutyrate),

methyltin tris(isooctyl-2-thiopropionate),

methyltin tris(decyl thioglycolate),

methyltin tris(isodecyl thioglycolate),

methyltin tris(dodecyl thioglycolate),

methyltin tris(dodecyl-3-thiopropionate),

methyltin tris(isodecyl-3-thiopropionate),

methyltin tris(dodecyl-4-thiobutyrate),

methyltin tris(octadecyl thioglycolate),

methyltin tris(octadecyl-3-thiopropionate),

methyltin tris(octadecyl-4-thiobutyrate),

methyltin tris(eicosanyl thioglycolate),

methyltin tris(eicosanyl-3-thiopropionate),

methyltin tris(cyclopentyl thioglycolate),

methyltin tris(cyclohexyl thioglycolate),

methyltin tris(cyclohexyl-3-thiopropionate),

methyltin tris(benzyl thioglycolate),

methyltin tris(benzyl-3-thiopropionate),

methyltin tris(phenyl thioglycolate),

methyltin tris(p-tolyl-3-thiopropionate),

methyltin tris(allyl thioglycolate),

methyltin tris(allyl-3-thiopropionate),

methyltin tris(allyl-4-thiobutyrate),

methyltin tris(crotyl thioglycolate),

methyltin tris(oleyl thioglycolate),

methyltin tris(oleyl-3-thiopropionate),

methyltin tris(oleyl-4-thiobutyrate),

methyltin octyl thioglycolate bis(decyl) thioglycolate,

methltin tris(methallyl thioglycolate),

methyltin tris(methallyl-3-thiopropionate),

methyltin tris(dodecenyl thioglycolate).

As the compounds of formula (1) there can be used any of those mentioned previously as well as dimethyltin bis(isodecyl thioglycolate) and dimethyltin bis- (isodecyl thio-3-propionate).

The trimethyltin compounds of formula (3) are the impurities still retained after forming the dimethyltin compounds, e.g., in the manner specified above.

The ADVASTAB TM-l81 FM mentioned below contained about 24 weight monomethyltin tris- (isooctyl thioglycolate), 0.6% trimethyltin isooctyl thioglycolate and the balance dimethyltin bis(isooctyl thioglycolate For food contact stabilizer work a similar formulation has been found satisfactory but containing approximately 24 weight monomethyltin tris(isooctyl thioglycolate). The food contact stabilizer formulation has been tentatively approved in Germany, The Netherlands and England.

Polyvinyl chloride bottles containing 2.2% of AD- VASTAB TM 181 FM were tested for migration of the stabilizer into (a) distilled water, (b) 3% acetic acid, (0) 10% ethanol, (d) 50% ethanol, and (3) peanut oil at 23 and 50 C. in tests lasting 3,10 and 24 days. In all cases, migration of the stabilizer was found to be well below 1 ppm. The maximum migration even at 50 C. barely exceeded 0.2 ppm, corresponding to about 0.03 mg/dm indicating the ADVASTAB TM 181 FS is well suitable for use as a stabilizer for polyvinyl chloride for the manufacture of food packaging material.

Polyvinyl chloride pipe having an inner diameter of 10 cm and a wall thickness of 3mm. containing approximately 0.7% ADVASTAB as a stabilizer was tested for suitability as a potable water pipe.

Sections of the pipe were filled with NaHCO solution and with Nal-ICO solution containing chlorine and stored for 2, 5 and 10 days. Both solutions were analyzed for migration of tin stabilizer. The migration in all cases was less than 0.01 mg/dm The potassium permanganate consumption of the NaHCO solution in all cases was less than 3 mg/l. The NaHcO -chlorine solutions had a mean value in the 10 days test of less than 2mg/m per day. Therefore, there is no health risk in using the pipe for potable water.

Sub-chronic toxicity studies were done on ADVAS- TAB TM 181 FS by -day rat feedings at levels of 0, 10, 30, and 300 ppm. There was no toxic effect at 100 ppm or lower and slight toxic effects were noted at 300 ppm.

As a result of other tests on ADVASTAB TM 181 FS, the British Industrial Research Association indicated that it could be included in the BIBRA/BPF Code of Recommendations at a maximum of 2.5% in polyvinyl chloride intended for food-contact use.

The following examples show that stabilizer formulations within the present invention impart excellent stability to polyvinyl chloride. The color ratings are on the usual 0 to 10 scale with 0 being colorless and 10 being black except in example 11 wherein the scale ranged from 0 being milky white to 10 being milky brown.

Example 8 Polyvinylchloride (Geon 103 Ep-8) 1000 Weight Stearyl alcohol 0.5 weight Stabilizer (Table 2) 2.0 weight The above formulations were mixed together on a two differential roll laboratory mill at C. for 5 minutes until thoroughly homogenzied. The resulting sheet was then taken from the roll at a thickness of 0.6 mm. and samples were heated in a gear-oven at C These samples were examined visually for rate of color development. In a further test, the two roll sheet was pressed in a press at 150 kg/cm for 50 minutes at C. at a thickness of 1 mm. The resulting sheets were examined visually for rate of color development.

Table 1 Stabilizer Table 4-Continued a Dimethyltin bis(isooctyl thioglycolate) 9 e 15 1809C y 10g yco 8 Com- Sta- Color of Test Piece (Mins.)

c Tr1methylt1n lsooctyl th1oglycolate pound bi- Weight d Dimethyltin dilaurate 5 Pans 2O 4O 6O 90 120 e Monomethyltin trilaurate 3 u 1.8 89.5 0 0 3 s f Dimethyltin bis(iso0ctyl maleate) g '2 8'5 8 8 8 g g g Monomethyltin tris(isooctyl maleate) 4 a 1.7 84.5 0 0 0 3 8 Table 2 Results Com- Sta- Color of Test Piece Color of pound bili- Weight (minutes)* Pressed No. zer Phr Parts 20 40 60 90 120 Sheet 1 a 1.8 89.5 0 0 0 3 8 Colorless 1 b 0.2 10.0 0 0 0 3 8 Colorless 1 c 0.01 0.5 0 O 0 3 8 Colorless 2 a 1.6 79.5 0 0 0 3 8 Colorless 2 b 0.4 20.0 0 O 0 3 8 Colorless 2 c 0.01 0.5 0 0 0 3 8 Colorless 3 d 0.8 90.0 5 Orange 3 e 0.2 10.0 5 5 10 Orange 4 d 1.6 80.0 6 7 10 Yellow Brown 4 e 0.4 20.0 6 7 10 Yellow Brown 5 f 1.8 90 l 3 7 10 Colorless 5 g 0.2 10.0 l 3 7 10 Colorless 6 f 1.6 80.0 1 3 9 10 Colorless 6 g 0.4 20.0 1 3 9 10 Colorless 7 a 2.0 100.0 1 1 2 7 9 Colorless 8 b 2.0 100.0 8 10 Yellow 9 d 2.0 100.0 5 5 10 Orange 10 e 2.0 100.0 6 10 Brown 1 l f 2.0 100.0 1 2 3 1O Colorless 12 g 2.0 100.0 10 Yellow 'Colorless(0) Yellow (3) Brown(7) Black (10) The results clearly show that the variation in the j b 88 8- 8 8 0 3 acidic components gave significant differences in heat 5 2 0 0 g 3 8 stab1l1ty. 5 b 0.4 20.0 0 0 0 3 8 The thioalkanoates had a remarkably improved ef- 2 2 8-? g 8 8 g 3 feet over the aliphatic carboxylate and the alkyl male 6 m 1 0 Q 0 2 3 am 6 n 0.01 0.5 0 0 o 2 8 7 a 1.4 69.5 0 0 0 4 8 7 b 0.6 30.0 0 O 0 4 8 EXAMPLE 9 7 c 0.01 0.5 0 0 0 4 8 PVC (polyvinyl chloride) sheets were prepared in a g g 28-8 8 8 l g manner similar to that described in Example 8 and g C 1 0 0 1 7 9 9 l 1.2 60.0 0 0 1 5 9 v were checked for rate of color de elopment 9 m 0.8 4040 0 O 1 5 9 T 3 S ilizer 9 n 0.01 0.5 0 0 1 5 9 able tab 10 a 1.0 50.0 0 l 4 9 10 a Dimethyltin bis(isooctyl thioglycolate) 10 b 0 l 4 9 10 b M th 1t. t t 1th. I l t 10 c 0.01 0.5- 0 l 4 9 10 fmome y 0 9 3 Y a 11 a 1.94 97.0 1 1 2 6 9 c Tr1methylt1n 1sooctyl thloglycolate b 8.8? 3 1 1 1 2 g h D1butylt1n b1s(1sooctyl thloglycolate) 12 h 18 90.0 0 l 2 4 9 1 Monobutyltm tr1s(1sooctyl th1oglycolate) 12 i 0.2 10.0 0 1 2 4 9 j Dioctyltin bis(isooctyl thioglycolate) 50 -2 28-8 8 l g 2 g k Monooctyltin tris(isooctyl thioglycolate) 14 j 1 1 2 4 6 9 1 Dim lin b' -eth 1h x leta-m rca to ro- 14 k 0.2 1 2 4 6 9 ethyt 15(2 y e y b e p p 15 j 1.6 80.0 1 l 3 6 9 p 15 k 0.4 20.0 1 1 3 6 9 m Monomethyltm tr1s(2-ethylhexyl-beta-mercapto- 16 a 2.0 100.0 1 1 2 7 9 propionate) 17 b 2.0 100 s 10 n Trlmethyltm 2-ethylhexyl-beta-mercaptoproicoloflessw) yellows) Brown) Blackflo) plonate The results clearly show that with the combination of Table 4 methyltin compounds there were obtained significantly improved effects over the butyltin compounds and the Results octyl tin compounds. The ratio of a and b comprising Com- Sta- Color of Test Piece (Mins.)* between 96:4 and 60:40 had the most outstanding img g Ph g' 20 40 6O I20 proved effects compared to other ratios in initial color and heat stability. 1 a 1.9 94.5 0 0 l 5 8 65 1 b 0.1 5.0 0 0 1 5 8 1 c 0.01 0.5 0 0 1 5 s w 2 l 1.9 94.5 0 0 0 2 8 Polyvinylchloride (Geon 103 Ep-S) 100 We ght part 2 m 0.1 5.0 0 0 0 2 8 Calcium Carbonate (OMYA-QOT) 3.0 welght part 2 n 0.01 0.5 0 O O 2 8 Low M.W. Polyethylene (AC-629A) 0.2 Weight part -Continued at 10 minute intervals and were checked for rate of discoloration.

Example l Calciu s O 6 weight pan Table 7 Stabilizer Paraffin Wax (ADVAWAX 165) 1.2 Weight part Titanium Oxidc weight pan Dimethyltin b s(isooctyl thloglycolate) Stabilizer 0.3 Weight part Monomethyltln tris(isooctyl thioglycolate) a b c Trimethyltin isooctyl thioglycolate h Dibutyltin bis(isooctyl thioglycolate) The above formulations were mixed together on a M b l i i (i l thioglycolate) two differential roll laboratory mill at 200 C. for 5 l0 pi ltin bis(isooctyl thioglycolate) minutes until thoroughly homogenized. The resulting Monooctyl tin tris(isooctyl thioglycolate) sheet was then taken from the roll at a thickness of 0.6 Table 8 mm. and samples were heated in gear-oven at 180 C. These samples were examined visually for rate of color Results development. Com- Sta- Color of Test Piece (Mins.)*

pound bil- Weight T bl 5 S bili No. izer Phr Parts 10 30 40 50 a Dimethyltin bis(isooctyl thioglycolate) g 8 28 g 2 Z 3 b IMonomethyltin tris(isooctyl thioglycolate) 20 c 1 3 6 7 9 c Trimethyltin isooctyl thioglycolate 2 760 2 5 6 9 b 0.48 24.0 1 2 5 6 9 J Dloctyltln b1s(lsooctylthloglycolate) c Q01 05 1 2 5 6 9 h 1.89 95.0 3 6 8 8 10 Table 6 i 0.10 5.0 3 6 s 8 10 j 1.89 95.0 4 7 8 9 10 k 0.10 5.0 4 7 8 9 10 Results 35 h F9 of Plece *Milkywhite(0) Milky-Yellow(5) Milky Brown( l0) pound bll- Weight lnltlal No. izer lPhr Parts Sheet l0 20 4O 50 The results at dynam1c heat stability clearly show that 1 1B. t4? 73.4 71 l 6 8 8 9 the combination of monomethyl tin compound into di 8-2 s i g g g g 30 methyl tin compound gave significantly improved stabi- 2 a 1 3 E 7 g g [0 50 lizing effect compared to the use of monobutyl tin com- 5 lb 0.8; 1.5 g g :8 :8 pound with dibutyl tin compound and the use of moe l. .2 it 3 m a 8 9 [0 i0 nooctyl tin compound with the dloctyl tln compound.

Colorless(0) Yellow(3) Brownt7) BluckHO) Example 12 Polyvinylchloride 100.0 Weight pans The results indicate that increase in the quantity of (Geon MBS Resin anc Ace B-l2) incorporated trlmethyltm compound decreased the (monobutyl Styrene resin) (10 weight pans heat stability effect. The methyltin stabilizer was better Stearyl Alcohol 0.5 Weight parts i 40 Stabilizer (Table 10) 2.0 Weight parts than the octyltin stabilizer.

The halogen-containing vinyl resin formulations were sheeted out in a manner similar to that described in Example 8 and were compared for rate of color develop- Example 1 l Polyvinyl chloride 100.0 Weight parts ment.

(Geon 103 Ep-8) Carcium Carbonate (OMYA-90T) 13.0 Weight parts Table 9 Stabilizer Low Molecular Pol eth lene (AC-629A) y y 0,2 weight n a Dimethyltin bis(isooctyl thloglycolate) Carcium Stearate 0.6 Weight parts i b Monomethyltin tris(isooctyl thioglycolate) DVAWAX I65) l fi 52:: c Trimethyltin isooctyl thioglycolate Stabilizer 0.3 Weight parts h Dibutyltin bis(isooctyl thloglycolate) j Dioctyltin bis(isooctyl thioglycolate) (In place of M88 there can be incorporated ABS (ac- The above formulations were rolled out on a two roll rylonitrile-butadiene-styrene terpolymer) and other differential roll laboratory mill at l90 C. The resulting 55 impact modifiers. there also can be added conventional sheets were taken from the roll at a thickness of 0.3 mm Processing aidSJ Table 10 Results Com- Sta- Color of Test Piece (Mins.)* Color pound bil- Weight lnitial of No. izer Ph Parts Sheet 20 40 Press Sheet l a 1.8 89.5 0 0 0 l 2 4 Colorless I b 0.2 10.0 0 0 0 1 2 4 Colorless I c 0.0l 0.5 O 0 0 l 2 4 Colorless Table 10-Cont1nl1ed Results Com- Sta- Color of Test Piece (Mins.)* Color pound bil Weight initial of No. izer Ph Parts Sheet 20 40 60 90 120 Press Sheet 2 a 1.6 79.5 0 O 0 l Colorless 2 b 0.4 20.0 v 0 0 O 0 1 v 5 Color less 2 c 0.01 0.5 0 0 0 -0 l .5 Color less 3 a l 2 59.5 0 0 0 2 3 9 Color less 3 b 0.8 40.0 0 0 0 2 3 9 Colorless 3 c 0.01 0.5 O O 0 2 3 9 Colorless 4 a 1.0 49.5 0 0 1 3 5 l0 Pale Yellow 4 b 1.0 50.0 0 0 l 3 5 l0 Pale Yellow 4 c 0.01 0.5 0 0 l 3 5 Pale Yellow 5 h 2.0 100.0 3 5 5 7 8 9 Yellow 6 j 2.0 100.0 4 5 6 8 8 9 Yellow 7 a 2.0 100.0 1 2 2 2 3 7 Colorless 8 b 2.0 100.0 0 1 9 7 Pale Yellow 9 c 2.0 100.0 3 5 5 7 8 9 Dark Yellow 'Colorlessw) Ycllow(3) Brown(7) BlackUO) i The results indicate the significantly improved effect ide resin withastabilizingly effective amount of a mixture of l) 60 to 96% of a compound having the formula and (2) 4 to 40% of a compound having the formula and having not over 0.6% of as an impurity in the stabilizer and where R is hydrocarbon of up to 20 carbon atoms and n is an integer of l to 3.

2. A composition according to claim 1 wherein the stabilizer has an LD of at least 695 when administered orally to rats.

3. A composition according to claim 2 wherein R is alkyl, cycloalkyl, alkenyl or benzyl and the LD of the stabilizer is at least 1000.

4. A composition according to claim 3 wherein R is alkyl of 4 to 12 carbon atoms and n is an integer of l to 2.

5. A composition according to claim 4 wherein R is alkyl of 8 to 12 carbon atoms.

6A composition according to claim 4 wherein the I amount.ottrimethyltincompound is not over 0.5% of the stabilizer.

7.A composition according to claim 6 wherein the amount of trimethyltincompouncl is not over 0.4% of the stabilizer.

35 I I I y I stabilizer is present in an amount of 0.1 to 5% by weight 8.-A composition according to claim 3 wherein'tlie of'the resin.

'9'.A composition according to claim 8 wherein they stabilizer is present in an amount of 0.1 to 2.5% by weight of the resin.

10. A composition according to claim 1 wherein not over 0.75% of the total tin present calculated as metal is present as trimethyltin compound.

11. A composition according to claim 1 wherein the stabilizer mixture contains 71 to 81% of (1) and 29 to 19% of (2) and the amount of trimethyltin compound in the stabilizer is not over 0.6%.

12. A composition according to claim 11 wherein the stabilizer has an LD of at least 695 when administered orally to rats.

13. A composition according to claim 12 wherein R is alkyl, cycloalkyl, alkenyl or benzyl.

14. A composition according to claim 13 wherein the LD of the stabilizer is at least 1000.

115. A composition according to claim 13 wherein R is alkyl of 4 to 12 carbon atoms and n is an integer of l to 2.

16. A composition according to claim 15 wherein R is alkyl of 8 to 12 carbon atoms.

17. A composition according to claim 16 wherein the LD of the stabilizer is at least 1000.

118. A composition according to claim 17 wherein the stabilizer is present in an amount of 0.1 to 2.5% by weight of the resin and the resin is a vinyl chloride resin.

19. A composition according to claim 15 wherein the amount of trimethyltin compound is not over 0.5% of the stabilizer.

Patent No. 3, 7, 7 Dated June 3, 1 75 Inventor) Lewis B. Weisfeld and Robert C. Witman It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Claim 1, line 47, change the formula to read:

-CH Sn ('5 (CH COOR 3 Claim 26, change the formula in column 25 to read:

-- CH3 S S(CH C0OR CH3 3 (CH2) cooR Claim 26, column 26, line 1, change the formula to read:

Signed. and Scaled this A ttes t:

RUTH C. MASON C. MARS Alta-Sling 0m HALL DANN Commissioner of Parents and Trademarks UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION a Patent No. 3,887,519 I Dated June 3, 1 75 Inventor-(S) Lewis B. Weisfeld and Robert C. Witman It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Claim 1, line 47, change the formula to read:

- CH -Sn '{S (CH COOR 3 Claim 26, change the formula in column 25 to read:

CH Sn S(CH C0OR cn S(CH COOR Claim 26, column 26, line 1, change the formula to read:

-CH -Sh '(S (CH COOR 3 Signed. and Scaled this [SEAL] twenty'ninth y f June1976 Arrest: RUTH L Anew; 52:3" c. MARSHALL mum I (ummlssmner of Patents and Tradem k 

1. A COMPOSITION COMPRISING A HALOGEN CONTAINING RESIN SELECTED FROM THE GROUP CONSISTING OF CHLORINATED POLYETHYLENE A VINYL HALIDE RESIN AND A VINYLIDENE HALIDE RESIN WITH A STABILIZINGLY EFFECTIVE AMOUNT OF A MIXTURE OF (1) 60 TO 96% OD COMPOUND HAVING THE FORMULA
 1. A composition comprising a halogen containing resin selected from the group consisting of chlorinated polyethylene a vinyl halide resin and a vinylidene halide resin with a stabilizingly effective amount of a mixture of (1) 60 to 96% of a compound having the formula
 2. A composition according to claim 1 wherein the stabilizer has an LD50 of at least 695 when administered orally to rats.
 3. A composition according to claim 2 wherein R3 is alkyl, cycloalkyl, alkenyl or benzyl and the LD50 of the stabilizer is at least
 1000. 4. A composition according to claim 3 wherein R3 is alkyl of 4 to 12 carbon atoms and n is an integer of 1 to
 2. 5. A composition according to claim 4 wherein R3 is alkyl of 8 to 12 carbon atoms.
 6. A composition according to claim 4 wherein the amount of trimethyltin compound is not over 0.5% of the stabilizer.
 7. A composition according to claim 6 wherein the amount of trimethyltin compound is not over 0.4% of the stabilizer.
 8. A composition according to claim 3 wherein the stabilizer is present in an amount of 0.1 to 5% by weight of the resin.
 9. A composition according to claim 8 wherein the stabilizer is present in an amount of 0.1 to 2.5% by weight of the resin.
 10. A composition according to claim 1 wherein not over 0.75% of the total tin present calculated as metal is present as trimethyltin compound.
 11. A composition according to claim 1 wherein the stabilizer mixture contains 71 to 81% of (1) and 29 to 19% of (2) and the amount of trimethyltin compound in the stabilizer is not over 0.6%.
 12. A composition according to claim 11 wherein the stabilizer has an LD50 of at least 695 when administered orallY to rats.
 13. A composition according to claim 12 wherein R3 is alkyl, cycloalkyl, alkenyl or benzyl.
 14. A composition according to claim 13 wherein the LD50 of the stabilizer is at least
 1000. 15. A composition according to claim 13 wherein R3 is alkyl of 4 to 12 carbon atoms and n is an integer of 1 to
 2. 16. A composition according to claim 15 wherein R3 is alkyl of 8 to 12 carbon atoms.
 17. A composition according to claim 16 wherein the LD50 of the stabilizer is at least
 1000. 18. A composition according to claim 17 wherein the stabilizer is present in an amount of 0.1 to 2.5% by weight of the resin and the resin is a vinyl chloride resin.
 19. A composition according to claim 15 wherein the amount of trimethyltin compound is not over 0.5% of the stabilizer.
 20. A composition according to claim 19 wherein the amount of trimethyltin compound is not over 0.4% of the stabilizer.
 21. A composition according to claim 13 wherein the stabilizer is present in an amount of 0.1 to 5% by weight of the resin.
 22. A composition according to claim 21 wherein the resin is a vinyl chloride resin.
 23. A composition according to claim 22 wherein the LD50 of the stabilizer is at least
 1000. 24. A composition according to claim 13 wherein the composition contains about 24% of (2), not over 0.6% trimethyltin compound and the balance (1).
 25. A composition according to claim 24 wherein the amount of trimethyltin compound is not over 0.4% of the stabilizer.
 26. A stabilizer composition comprising a mixture of (1) 60 to 96% of a compound having the formula
 27. A composition according to claim 26 wherein (1) is 71 to 81% and (2) is 19 to 29%.
 28. A composition according to claim 27 wherein (2) is about 24%.
 29. A composition according to claim 28 wherein (3) is not over 0.4%. 